Rotary brush

ABSTRACT

A POWER-DRIVEN ROTARY BRUSH HAVING A COLLAR OF PLASTIC SHEET MATERIAL ENCIRCLING THE HOLDER PORTION OF THE BRUSH AND EXTENDING A SHORT DISTANCE BEYOND SUCH HOLDER ABOUT THE BRUSH MATERIAL WHERE SUCH BRUSH MATERIAL EMERGES FROM THE HOLDER. THE PLASTIC COLLAR IS FOLDED IN THE REGION OF THE BRUSH MATERIAL TO PRESENT A FOLDED EDGE THERETO AS WELL AS TO INCREASE THE THICKNESS OF THE COLLAR IN SUCH REGION.

United States Patent O 3,562,833 ROTARY BRUSH Vernon K. Charvat, Bay Village, Ohio, assignor to The Sherwin-Williams Company, Cleveland, Ohio, a corporation of Ohio Filed June 26, 1969, Ser. No. 836,908 Int. Cl. A46b 13/02 U.S. Cl. 15-180 25 Claims ABSTRACT OF THE DISCLOSURE A power-driven rotary brush having a collar of plastic sheet material encircling the holder portion of the brush and extending a short distance beyond such holder about the brush material where such brush material emerges from the holder. The plastic collar is folded in the region of the brush material to present a folded edge thereto as well as to increase the thickness of the collar in such region.

This invention relates, as indiciated, to a power-driven rotary brush having a plastic collar thereabout designed to regulate and control the action of the brush material m use.

As disclosed in my prior U.S. Pat. No. 2,989,767, power-driven rotary end brushes have been provided with plastic sheet material collars which extend only a short distance beyond the lip of the cup-like holder of the brush, thereby to regulate and control the action of the brush bristle material and more particularly to inhibit long fracture of such brush bristles when the latter flare in a generally radially outward direction under the influence of centrifugal force in use. Brushes of this type have been manufactured and sold in large quantities and have met with substantial commercial acceptance. A small band or ring of plastic material, such as foamed polyurethane, for example, has sometimes also been placed about the brush 'material in the region where the latter emerges from the cup-like holder and a plastic tape collar then tightly wrapped around the cup and ring to enhance the grip of such collar on the brush material. Plastic collars as described have been particularly satisfactory and effective when utilizing quite small gauge bristle material, such as Wire having a diameter of .005 inch, for example. They have not ordinarily been employed, however, when using twisted tufts of Wire bristle material as such tufts tend to tear and break down the short plastic collar encircling the same when under the influence of centrifugal force in use. Also, when utilizing end brushes of the type having a substantial outwardly fiaring lip instead of a constricted lip there may be more of a problem in causing the short plastic collar reasonably firmly to engage the brush bristle material, and the insertion of an inner band to enhance such engagement involves an additional step in the"manufacturing operation.

It is accordingly a principal object of this invention to provide a novel power-driven rotary end brush having a collar of plastic sheet material encircling the same and extendng a short distance only beyond the lip of the holder portion, which collar will be particularly resistant to tearing or otherwise breaking down when the brush is placed in use.

Another object is to provide such rotary end brush which will be relatively simple and inexpensive of manufacture.

Still another object is to provide such rotary end brush in which the lip of the collar is integrally reinforced and also thickened to provide additional bulk where desired and thereby closely engage the brush material in the region where the latter emerges from the holder.

Patented Feb. 16, 1971 `Further objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but certain of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is an elevational view of a power-driven rotary end brush embodying the principles of this invention;

FIG. 2 is a section taken on the line 2-2 of FIG. 1 through the outer plastic collar, without however sectioning the brush itself;

PIG. 3 is a view corresponding to that of FIG. 2 but illustrating a somewhat different form of end brush;

FIG. 4 is an iso'mertic view, partly broken away, showing a plastic sleeve element suitable for employment in accordance with this invention;

FIG. 5 is a semi-diagrarnmatic view showing the manner in which a strip of plastic tape may be continuously progressively folded for use as collar material in accordance with the invention; and

PIG. 6 is an enlarged fragmentary cross section through the lip of a cup-shaped holder of the FIG. 1 type showing a plurality of plies of folded plastic tape secured theretO.

Now referring to said drawing, and more particularly to FIGS. 1 and 2 thereof, a poWer-driven rotary end brush is shown of the general type disclosed in :Nelson U.S. Pat. No. 3,`370,313, comprising a steel cup-shaped holder portion 1 provided with a coaxial drive stem or shank 2. Such holder portion is tightly encircled with a plastic sheet material collar 3 which extends a short distance beyond the lip 4 of such holder and closely embraces the twisted tufts of Wire brush bristle material 5. As best shown in FIG. 2, the plastic collar is folded inwardly at '6 to present a folded lip portion to the twisted tufts of brush bristle material when the latter are caused to flare generally outwardly under the action of centrifugal force as the brush is rotated at high speed about its longitudinal axis in use. The lower edge 7 of the plastic collar will desirably extend to enclose and cover at least a portion of the underside of the holder 1, both to protect the work if the holder accidentally comes in contact therewith in use 'and also to assist in preventing loosening or tearing off of the collar during brush operation under rough operating conditions.

The plastic collar of this invention may likewise be utilized with other types of power-driven rotary end brushes, such as, for example, the brushes disclosed in 'Less Pat. No. 3,10`6,739 and Nelson Pat. No. 3,312,993.

As shown in FIG. 3, however, the holder may be of the general type disclosed in Benyak Pat. No. 2,449,158 having a constricted lip 8, with slightly crimped fine wire brush bristle material 9 secured within the cup-shaped holder 10 as taught in such patent or by means of solder, for example. By employing a collar 11 of plastic sheet material which is folded at 12, not only is a yielding support provided for the brush bristle material 9, which tends to reduce long breakage in use, but the inwardly projecting portion of the collar is enabled more readily and firmly to engage the brush bristle material in the region where it emerges from the holder. Moreover, the folded plastic edge thus presented to the bristles is much more resistant to tearing and Cutting by the Wire bristles as the latter fiare outwardly under the influence of centrifugal force in use.

FIG. 4 of the drawing illustrates one type of plastic sheet material collar which may be utilized in accordance with the principles of the invention, such collar comprising a short length of tubular plastic material one end of which is folded inwardly at 14 to provide a short portion 15 of double thickness. This folded sleeve or tube, if of somewhat elastomeric material, may be stretched and slipped over the holder With the doubled portion engaging the brush bristle material in the region where the latter emerges from such holder. As explained below, such sleeve may also be selected from certain types of plastic sheet material which may be caused to shrink into position when properly treated. The plastic collar of this invention may be formed from a continuous length of plastic tape 16 which may be continuously withdrawn from a supply spool and progressively folded at 17 to provide a narrow edge portion 18 of double thickness. As many turns of such tape as may be desired may then be wrapped about the cup-shaped holder 1 or to provide the short projecting collar portion of proper thickness (see FIG. 6).

Such plastic tape material may be selected for its ability to shrink substantially upon subsequent treatment and also for its ability when thus shrunk to yield in at least a somewhat resilient fashion. A particular suitable plastic for my purpose has proven to be an irradiated polyethylene film commercially available as Irrathene manufactured by Chemical & Metallurgical Division of General Electric Company, Pittsfield, Mass. When a number of turns of such tape have been wrapped on the cup-shaped holder, such tape may be painted with a 10 percent solution of dicumyl peroxide in Xylene. The end of the Irra-` thene tape may then be secured with a pressure-Sensitive tape such as Mylar tape (a polymer of ethylene terephthalate). The brush assembly may then be heated in an oven for one-half hour at a temperature of from about 105 degrees to about 115 degrees C. and the heating thereafter continued for another half hour at a temperature of about 135 degrees to about 150 degrees C. The Mylar tape may then be removed, and the brush is ready for use.

When treated as described, the Irrathene shrinks strongly to embrace the cup-shaped holder as shown in the drawing, and the portion extending beyond the lip of the cup is drawn inwardly tightly to encircle and embrace the tuft of bristles forming a protective collar for such bristles.

When using an end brush having a cup diameter of from about 1/2 inch to about 3A inch, it has been found desirable for the plastic collar to extend only from about 1/8 inch to about '078 inch beyond the lip of the cup, with 3/16 inch commonly being preferred. Under these conditions, the desired outwardly flaring movement of the brush bristle material in use is adequately permitted while yieldingly Controlled to prevent excessive concentration of stress in this region, and the life expectancy of the brush is accordingly much enhanced. Not only is a much increased brush life achieved by employment of my invention, but also danger to the operator is considerably reduced since broken brush wires may be thrown off from ordinary brushes at quite high speeds.

Other plastic material such as rubber and polyvinyl chloride may be employed for the collar, being wrapped under tension and secured in this condition by means of appropriate cement. Also, while particularly valuable for use With brushes having wire bristles, and especially fine Wire bristles, my new construction is also of value in brushes utilizing other types of bristles including wire of other metals, plastic-coated Wire, nylon-coated glass fiber, and Tampico fiber. In order to secure the desired close engagement of the collar wit'h the 'brush bristle material where the latter emerges from the cup-shaped holder, the plastic collar will normally be folded inwardly as shown and a plurality of turns of the folded plastic tape 16 may be utilized in this manner. On the other hand, certain advantages of the invention, including resistance to tearing, are also obtained even when the plastic collar is folded outwardly instead. It will be appreciated that the plastic collar may comprise multiple plies of thin plastic tape rather than a single folded layer as generally illustrated in FIGS. 2 and 3. Thus, FIG. 6 shows the preferred manner in which the folded plastic tape is wrapped about the brush, although there may be more turns than are semi-diagrammatically illustrated in such figure. It is possible to obtain a strongly reinforced lip on the collar without building up such a thick plastic layer on the holder as to make the latter inconveniently bulky in use. Even when the lip of the cup is outwardly flaring, which is frequently a desirable feature, the reinforced plastic collar is effective in embracing and controlling the brush bristle material. If desired, a short foamed plastic insert or Washer may also be provided about such brush bristle material where the latter emerges from the holder beneath the collar. Ordinarily, however, the collar of this invention has been found to be entirely satisfactory for its intended purpose without any further modifications of this nature.

The preferred bristle material is .005-.010 inch diameter steel wire, especially stainless steel, and .005 inch diameter Wire is preferred. T=he cup-shaped holder may be of steel turned on a screw machine or impact extruded, or it may be of a rigid molded plastic such as 6,6 nylon. For hard use vthe steel cup is preferred. As indicated, the invention is particularly advantageous when employing small diameter holders and fine Wire bristle material, and the cup OD will ordinarily be 5A; inch or 1/2 inch for most purposes. Generally, the plastic collar should project only about 9/16 inch beyond the lip of the cup, and frequently even slightly less. The folded lip 12 and the embracing of the outer bottom surface of the holder as shown in FIG. 3 assist in maintaining the plastic collar in place despite rough use of the tool, and a bonding agent may also be utilized to adhere the collar to the holder.

'When employing a length of tubing as the collar, as shown in IFIG. 4, elastomeric Neoprene (polychloroprene) is preferred which may desirably have an ID slightly less than the OD of the cup onto which it is to be fitted by stretching, its contraction or shrinking thereupon assisting in holding it in place as well as shrinking in the projecting portion about the bundle of brush bristles where the latter emerge from the cup. Such Neoprene tubing may have a thickness of, for example, .062 inch and an ID of 7/16 inch when intended for mounting on a 5/8 inch OD cup. The projecting folded portion of the Neoprene collar is resiliently yieldable in accordance with the degree of bristle flare. Thus, the folded portion of the tubular sleeve engaging the bristles is twice the thickness of the portion of the sleeve surrounding the cup.

Similarly, when using the tape wrap, six plies will provide a total thickness of .060 inch on the cup but double such thickness where extending beyond the lip of the cup. This relationship may be modified, if desired, by combining a certain number of folded wraps with a certain number of unfolded wraps to obtain any desired thickness of the portion beyond the cup lip. Ordinarily, the wraps will not be built up to a thickness of more than 0.10 inch on the cup.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, providing the features stated in any of the following claims, or the equivalent of such, be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. In a rotary brush having a holder and brush bristles extending therefrom in a direction generally parallel to the axis of rotation of said holder;` a plastic collar encircling said holder and extending a short distance therebeyond to embrace said bristles where they emerge from said holder, said collar being of plastic sheet material folded to present a folded edge encircling said bristles.

2. The brush of claim '1, wherein said 'holder is of cup shape and said collar is folded inwardly.

3. The brush of claim 2, wherein the inwardly folded portion of said collar extends beyond the lip of said cup only, closely to embrace said bristles.

4. The brush of claim 2, wherein said bristles are of fine gauge Wire.

5. The brush of claim 2, wherein said bristles are in the form of twisted tufts of fine gauge Wire.

6. The brush of claim 3, wherein said bristles are of fine gauge Wire and said folded collar extends from about 1A; inch to about 3/8 inch beyond the lip of said cup.

7. The brush of claim` 3, wherein said folded portion is bonded to the lip of said cup.

8. The brush of claim 1, wherein said plastic sheet materail is thus folded inwardly and Wrapped about said holder in a plurality of turns.

9. The brush of claim '3, wherein said plastic sheet material extends to and engages the underside of said holder.

10. In a rotary brush having a holder and brush bristles extending therefrom; a fiexible s'heet material collar embracing said bristles in the region Where they emerge from said holder, said collar being folded to present a folded edge for engagement by said bristles.

11. The brush of claim 10, wherein said collar is secured to said holder.

12. The brush of claim 11, wherein the folded portion of said collar extends beyond said holder only.

113. The brush of claim :12, wherein said fiexible sheet material is plastic sheet material.

14. The brush of claim 12, wherein said fiexible sheet material is resiliently deformable plastic sheet material.

1'5. The brush of claim 12, wherein said 'fiexible Sheet material is polychloroprene.

16. In a power driven rotary end brush having a cupshaped holder and brush bristles secured therein and extendng therefrom in a direction generally parallel to the axis of rotation of said holder: a plastic collar encircling said holder and extendng a short distance beyond the lip of such cup to embrace said bristles where they emerge from said holder, said collar being of plastic tape wrapped about said holder and having an inwardly folded edge portion encircling said bristles.

17. The brush of claim 16 wherein said tape is Shrinkfitted on said brush.

1.8. The brush of claim '16, wherein said collar is of reduced internal diameter where thus embracing said bristles to engage and support the latter but is resiliently yielding when said bristles tend to flare radially outwardly under the action of centrifugal force in use.

19. The brush of claim 18, wherein said collar extends from about 1A; inch to about 1A; inch beyond the lip of said cup-shaped holder, said folded portion encircling said bristles only.

20. In a power driven rotary brush having a cupshaped holder and twisted Wire bristle tufts secured therein and extendingr therefrom in a direction generally parallel to the axis of rotation of said holder: a plastic sheet material collar encircling said holder and extending a short distance beyond the lip of said cup, the material of said collar being folded inwardly where encircling said bristle tufts in the region beyond said lip, thereby presenting a folded edge to said tufts when the latter flare outwardly as the brush is rotated in use.

21. The brush of claim 20, wherein the inwardly folded portion of said plastic sheet material extends beyond said lip only, thereby more closely and firmly to engage said tufts and to provide increased collar thickness in such region.

22. In a power driven rotary brush having a bristle holding portion and brush bristles secured therein and extending therefrom, a collar of plastic sheet material embracing said bristles in the region where they emerge from said holding portion, With said sheet material being folded to present a folded outer edge to said bristles Where thus embracing the latter.

23. In a power driven rotary brush having a cupshape holder and brush bristle material secured therein and extending therefrom, a fiexible sheet material collar encircling and secured to the outer surface of said holder and projecting a short distance beyond the lip of said cup to embrace said bristle material emerging therefrom, said collar being of greater thickness in such projecting portion than where thus encircling said holder.

24. The brush of claim 23, wherein said sheet material is elastomerc.

25. The brush of claim 23, wherein said sheet material is tubular polychloroprene.

References Cited UNITED STATES PATENTS 209,279 10/1878 Marsden 15 168 1,720,017 7/1929 Touchstone 15-180 2,525,947 10/1950 Rose 15-181X 2,989,767 6/1961 Charvat 15-180X 3,225,372 12/ 1965 Carpenter 15-29 PETER FELDMAN, Primary Examiner 

